1. Field of the Invention
The present invention relates to identification systems and, more particularly, to a call tracing and identification system for a telephone network for rapidly tracing and identifying the calling party's telephone number directly to the called party.
2. Description of the Prior Art
With the numerous advantages and benefits of the modern telephone have come certain disadvantages, not the least of which has been the vulnerability of telephone subscribers to the persistent receipt of malicious, annoying and criminal telephone calls. Since the ringing signal of the telephone normally carries with it no indication as to the nature or identification of the calling party, a subscriber who has become the target of such harassment must either ignore all telephone calls or subject himself to continued annoyance. Since the calling party's anonymity remains intact throughout the duration of his criminality, it is often virtually impossible to prevent continued disturbance of the called party without changing the telephone number and withholding the listing of the new number in the telephone directory. Obviously, this has the disadvantage of requiring the innocent victim, namely the called party, to notify all friends, relatives and associates of the new telephone number and, more importantly, is no guarantee that a similar situation would not arise again in the future.
In view of the seriousness of the above-described situation, stringent laws have been passed to deter the malicious caller from perpetuating such conduct, and a number of complex call tracing systems have been developed in an effort to reveal the identity of the calling party. The prior art, as exemplified by U.S. Pat. Nos. 2,045,146, 3,336,445, 2,879,338, 2,963,553, 3,336,445, 3,385,933, 3,431,364, 3,471,647, 3,516,062, 3,522,385, 3,674,941, 3,576,951, 3,686,440, 3,702,902 and 3,787,626, is generally cognizant of identification systems for communication networks including call tracing equipment which is designed to be utilized at or in connection with local telephone exchange equipment to identify the telephone number of a party who has placed a malicious or annoyance call to a particular subscriber. The prior art identification systems generally have one or more deficiencies such as being quite complex, being unsuitable for telephone networks, being excessively expensive, requiring an excessive time interval in order to properly identify the calling party which allows the malicious caller to recognize such delay and hang up before the system has had a chance to complete the trace thereby avoiding identification, producing signals interfering with normal communication or warning the malicous caller, etc.
In the course of developmental efforts in the field of telephone call tracing, it has also been discovered that a need exists for an economical yet effective system for rapidly identifying the telephone number of all calling parties whether a called subscriber answers his phone or not. In this way, not only will malicious or prank calls be traced, but calls missed while a subscriber is away from his telephone can also be identified simply and automatically.
While numerous attempts have been made to solve these and other related problems, the solutions heretofore proposed have only been partially satisfactory due to their complexity, high cost, slow speed of operation, required interconnection and disruption of local telephone exchange equipment, and overall ineffectiveness in combating the problem of the malicious or prank caller.